Apparatus for gaseous fuel analysis



l 1950 R. G. RUSSELL arm. 2,523,721

APPAI QATUS FOR GASEOUS FUEL ANALYSIS Filed Aug. 14, 1944 VENTOR. Poer/ 6. l sse and 1,: Babe/'7 Harper Donna/d overcome the foregoing objections. ent invention the fuel mixture in the burner proper isanalyzed before it is delivered into the Patented Sept. 26, 1950 UNITED STATES PATENT- OFFICE-Q APPARATUS FOR GASEOUS FUEL ANALYSIS Robert G. Russell and Robert Harper Donnald, Newark, Ohio, assignors to Owens-Corning Fiberglas Corporation, Toledo, Ohio, a corporation of Delaware Application August 14, 1944, Serial No. 549,472

4 Claims.

: l ,l'l'llS invention relates to equipment for determining the characteristics of a combustible fuel mixture.

In the operation of heating chambers served by gas burners, it is customary to periodically analyze the products of combustion either at the stack or within the chamber proper by employing any one'of the various gas analyzers available for this purpose. This practice is not entirely satisfactory because it merely indicates the composition of the combined fuel mixture delivered by all of the burners serving the chamher. and, therefore, does not indicate individual burner performance. Furthermore, readings taken from the stack or from the interior of the heating chamber do not necessarily indicate the nature of the fuel mixture supplied by the burners as outside air may find its way into the stack or heating chamber and mix with the products of combustion. This is particularly true in cases where the burners are not of the sealed type or,

in other words, where ,a space exists between the burner nozzles and' the heating chamber Walls.

It is a principal object of the invention to By the presheating chamber. Thus, the actual fuel mixture which is subsequently burned by each of the burners maybe individually analyzed with the result that the reading obtained not only is a true indication of the quality of the actual fuel .mixture supplied to the heating chamber regardless of air currents existing in the heating chamber or stack, but, in addition, fault burners may be quickly found and corrected.

Another object of this invention is to analyze the actual fuel mixture flowing through the burner in advance of its combustion by employment of a conventional gas analyzer acting on products of combustion. This is accomplished by burning a sample or specimen of the actual fuel mixture flowing through a burner in amanner which enables the resulting products of combustion of this fuel mixture to be introduced to a suitable gas analyzer capable of indicating the Various constituents of the fuel mixture and the amounts of the latter.

A further feature of this invention is to provide apparatus for accomplishing theabove results capable of being selectively attached to the burners with the minimum amount of effort and without disturbing the burners or any part of the heating chamber.

V, The foregoing as well as other objects .will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein:

Figure 1 is a diagrammatic side elevational view of a furnace having a series of burners and indicating equipment constructed in accordance with this invention;

Figure 2 is a semi-diagrammatic sectional view of the equipment forming the subject matter of this invention; and

Figure 3 is a fragmentary sectional view of one of the samplers.

Figure 1 of the drawing illustrates diagrammatically a typical heating chamber 10 havinga plurality of burners ll sealed in one side wallof the chamber in the manner clearly shown in Figure 2 and having a nozzle l2 for discharging the desired fuel mixture into the heating chamber. The fuel, such as ordinary fuel gas, is introduced into a mixing chamber l3 at thebottom of each burner by means of a supply line l4 and is mixed with a quantity of air introduced into the mixing chamber 13 by a supply line [5. The proportion of air and gas admitted to the burners is, of course, predetermined to provide the most eflicient fuel mixture at the nozzle l2.

However, the condition of the burner frequently alters the quality of the mixture and, therefore, in the interests of efficient performance it is desirable to periodically analyze the fuel mixture or test its combustible characteristics. The specific gas analyzer employed forms no part of this invention and any one of the Various available analyzers capable of analyzing products of combustion and indicating the different constituents of the fuel mixture as well as the quantities of these constituents may be used. For the purpose of this description, the analyzer is indicated generally in the drawing by the reference character [6 and is capable of indicating the quantities of CO, 02 and CO2 in the products of combustion resulting from burning the fuel mixture.

In accordance with this invention, a sample of the actual fuel mixture burned is taken from each individual burner in such a manner that the sample is representative of the fuel mixture across the entire cross-section of the passage of the burner. The sample is taken at a point immediately in advance of the entrant portionof the nozzle 12 and the products of'combustion of each specimen or sample are submitted to the analyzer I6. In detail, a mixture collecting tube l1 extends through the outer wall of each burner immediately adjacent the entrant portion of the burner nozzle I 2. As shown in Figure 2, the tube I! projects transversely of the gas passage in the burner to a point adjacent the inner wall of the burner and a plurality of intake openings l8 are formed in the side of the tube facing the direction of flow of the gas mixture. These openings l8 are provided along the entire length of the portion of the tube I! in the burner so that they are spaced across the diameter of the gas passage. As a result, the fuel mixture collected by the tube is representative of the mixture flowing throughout substantially the entire cross-section of the burner passage.

The fuel mixture collected by the tube I! is conducted to a burner I9 through length of flexible tubing having one end suitably con nected to the tube I1 and having the opposite end connected to the burner [9. The burner i9 is supported in a combustion chamber 2| preferably formed of a heat resistant transparent material so as to enable the flame to be viewed and analyzed by sight, if desired. The bottom of the chamber 2| is closed by a cap 22 and a sealing compound is inserted between the cap and chamber 2| to avoid any possibility of air escaping into the lower end of the chamber. The top of the chamber 2| is closed by a removable cap 23 centrally apertured to receive the intake tube 24 of the gas analyzer is. The opening in the cap 23 for receiving the tube 24 is sufficiently larger than the tube to enable the escape of ex haust gases from the tube. The possibility oi air escaping into the tube through the exhaust port and causing a false reading of the gas analyzer is remote because the products of combustion resulting from burning the sample gas mixture in the chamber 2| flowing toward the exhaust port and are at a somewhat higher pressure than the ambient atmosphere. Furthermore, a perforated baffle 25 is fixed in the chamber 2| at the lower end of the tube 24 and resists any tendency for air to bleed into the tube 24.

Following the present invention, a sample of the actual fuel mixture passing through a selected burner H is burned in the chamber 2| and the products of combustion of this mixture are introduced to the analyzer |6 which indicates the characteristics of the mixture. By following this procedure with each burner II it is possible to adjust the system to insure uniform operation at maximum efficiency. Moreover, owing to the simplicity of the testing operation, frequent tests are practical and satisfactory performance over a long period is insured.

Attachment of the equipment previously described to the burners l i is simplified by permanently fixing the collecting tubes I! in their respective burners l and by providing each tube l 1 with a valve 26 mounted in a position enabling the same to be readily manipulated. Thus the equipment including the analyzer, the tube 2|, and the flexible tube 20, may be readily attached to a burner by slipping the free end of the flexible tube 20 over the end of the collecting tube projecting from the burner and may be placed in operation by opening the valve 26 to supply fuel 'mixture to the burner l9.

We claim:

1. Apparatus for gauging the operation of a gas-fired furnace having a series of burners for supplying a combustible mixture of gas and air to the furnace and gas supply lines connected to the burners, the combination of gas and air mixers individual to the burners and located in the gas supply lines in advance of each burner, a device for indicating the characteristics of the gas and air mixture flowing to the burner includin a combustion chamber, a conduit closed throughout its length to the atmosphere and connected at one end to the combustion chamber and at its other end releasably connectable to the gas supply lines at points between said gas and air miXers and said burners to by-pass a portion of the gas and air mixture from the supply lines to said combustion chamber, means for burning the by-passed gas and air mixture in the combustion chamber, means sealing the combustion chamber against the entry of atmospheric air into the region of said burning, and viewing means in the wall of said combustion chamber to permit visual inspection of the combustion taking place within the chamber.

2. Apparatus for gauging the operation of a gas-fired furnace having a burner for supplying a combustible mixture of gas and air to the furnace and a gas supply line connected to the burner, the combination of a gas and air mixer in the gas supply line in advance of said burner, a device for indicating the characteristics of the gas and air mixture flowing to the burner including a combustion chamber, a conduit closed throughout its length to the atmosphere and connected at one end to the combustion chamber and at its other end to the gas supply line at a point between said gas and air mixer and said burner to by-pass a portion of the gas and air mixture from the supply line to said combustion chamber, means for burning the by-passed gas and air mixture in the combustion chamber, means sealing the combustion chamber against the entry of atmospheric air into the region of said burning, and means for conducting the products of combustion resulting from said burning to a gas analyzer.

3. Apparatus for gauging the operation of a gas-fired furnace having a burner for supplying a combustible mixture of gas and air to the furmace and a gas supply line connected to the burner, the combination of a gas and air mixer in the gas suppl line in advance 'of said burner, a device for indicating the characteristics of the gas and air mixture flowing to the burner including a combustion chamber, a conduit closed throughout its length to the atmosphere and connected at one end to the combustion chamber and at its other end to the gas supply line at a point between said gas and air mixer and said burner to by-pass a portion of the gas and air mixture from the supply line to said combustion chamber, means for burning the by-passed gas and air mixture in the combustion chamber, means sealing the combustion chamber against the entry of atmospheric air into the region of said burning, and a window in the wall of said combustion chamber to permit visual inspection of the combustion taking place within the chamber.

4. Apparatus for gauging the operation of a gas-fired furnace having a series of burners for supplying a combustible mixture of gas and air to the furnace and gas supply lines connected to the burners, the combination of gas and air mixers individual to the burners and located in the ply lines at points between said gas and air mixers and said burners to by-pass a portion of the gas and air mixture from the supply lines to said combustion chamber, means for burning the bypassed gas and air mixture in the combustion chamber, means sealing the combustion chamber against the entr of atmospheric air into the region of said burning, and means for conducting the products of combustion resulting from said burning to a gas analyzer.

ROBERT G. RUSSELL. ROBERT HARPER DONNALD.

REFERENCES CITED The following references are of record in the file of this patent:

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